Chapter 9: Cellular Respiration and Fermentation Flashcards
Fermentation
- Catabolic process that makes a limited amount of ATP from glucose without an electron transport chain
- Produces a characteristic end product (i.e. ethyl alcohol or lactic acid)
Aerobic Respiration
- Catabolic pathway for organic molecules
- Uses oxygen as the final electron acceptor in an electron transport chain
- Ultimately produces ATP
- Most efficient catabolic pathway
- Carried out in most eukaryotic cells and many prokaryotic organisms
Cellular Respiration
- Catabolic pathways of aerobic and anaerobic respiration
- Break down organic molecules and use an electron transport chain for the production of ATP
Redox Reaction
- Chemical reaction involving the transfer of one or more electrons from one reactant to another
- Short for reduction-oxidation reaction
Oxidation
Complete or partial loss of electrons from a substance involved in a redox reaction
Reduction
Complete or partial addition of electrons to a substance involved in a redox reaction
Reducing Agent
Electron donor in a redox reaction
Oxidizing Agent
Electron acceptor in a redox reaction
Electron Transport Chain
Sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP
Glycolysis
- Series of reactions that ultimately splits glucose into pyruvate
- Occurs in almost all living cells
- Serves as the starting point for fermentation or cellular respiration
Citric Acid Cycle
- Chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules to carbon dioxide
- Occurs within mitochondria
- Second major stage in cellular respiration
- Also called the Krebs Cycle
Oxidative Phosphorylation
- Production of ATP using energy derived from the redox reactions of an electron transport chain
- 3rd major stage of cellular respiration
Substrate-Level Phosphorylation
Enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism
Acetyl CoA
- Acetyl coenzyme A
- Entry compound for the citric acid cycle in cellular respiration
- Formed from a fragment of pyruvate attached to a coenzyme
Cytochrome
Iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells
ATP Synthase
- Complex of several membrane proteins that provide a port through which protons diffuse
- Functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP
- Found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes
Chemiosmosis
Energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP
Proton-Motive Force
- Potential energy stored in the form of an electrochemical gradient
- Generated by the pumping of hydrogen ions across biological membranes during chemiosmosis
Alcohol Fermentation
Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing of carbon dioxide
Lactic Acid Fermentation
Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+ with no release of carbon dioxide
Obligate Anaerobe
- Organism that only carries out fermentation or anaerobic respiration
- Such organisms cannot use oxygen and may in fact be poisoned by it
Facultative Anaerobes
Organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present
Beta Oxidation
Metabolic sequence that breaks fatty acids down to two-carbon fragments that enter the citric acid cycle as acetyl CoA
